Overhead power conveyor systems are very widely used in all manner of manufacturing and material handling operations. Conveyor systems of this type typically include a suspended guide rail, which may comprise an I-beam, T-beam, or box-section, and a articulable conveyor carried by the guide rail. The conveyor typically comprises wheeled trolley elements which engage and ride in or on the guide rail, and flexible linkage means, such as a cable or chain links, which interconnect the trolleys. Carrier elements are typically connected to the trolleys and depend beneath the guide rail so that articles to be conveyed can be readily attached to the conveyor. These types of conveyors are extremely versatile in that they can be arranged to extend angularly upwardly and downwardly, as well as in curved or circuitous routes.
As will be appreciated, efficient operation of overhead conveyor systems calls for regular maintenance to avoid excess accumulation of dirt and debris on the guide rail and conveyor. However, considering that it is not unusual for a typical system to extend for hundreds or thousands of feet, effective cleaning of the conveyor system can be extremely time-consuming. Nevertheless, smooth, efficient operation of the conveyor requires that build-up of debris be avoided.
While for many overhead conveyor systems efficient cleaning principally facilitates smooth operation, the deleterious effects of debris accumulation can be significant in conveyor systems used in connection with painting operations, and more particularly, electrostatic painting. In painting operations of this nature, a voltage potential is established between a paint-dispensing nozzle and an article receiving paint, whereby the paint spray or droplets are electrostatically attracted to and coat the article. This type of painting is recognized as desirably avoiding waste since paint "overspray" is abated.
In a typical electrostatic painting operation employing an overhead conveyor for transport of the articles being painted, it will be appreciated that the conveyor system itself plays an integral role in establishing the desired electrical voltage potential between the paint and the article. Ordinarily, the conveyor system comprises part of the potential-establishing circuit, with the metallic components of the conveyor (i.e., the guide rail, trolleys, carrier elements, etc.) acting to establish the electrical potential for articles conveyed thereby.
Thus, it will be appreciated that in an electrostatic painting environment the implications of effectively cleaning the conveyor system go beyond smooth and trouble-free operation; effective cleaning is required so that components of the movable conveyor are and remain effectively grounded to the guide rail during painting operations. A loss of ground owing to a buildup of debris, such as paint, grease, and the like, results in less efficient painting of the article, wasted paint and concomitant pollution of the environment.
In the past, various attempts have been made to perfect effective conveyor cleaning devices. For example, one previous device comprises power-driven rotary brushes arranged to contact surfaces of the conveyor as it moves along its guide rail. However, experience has shown that not only is this particular device ineffective in providing the desired cleaning, the rotating brush assemblies undesirably tend to "sling" debris from their surfaces onto the products being carried by the conveyor and work spaces below. Further, the power-driven nature of such a device adds to the expense of its initial installation and subsequent operation.
In view of the efficient operation which is promoted by effective cleaning of an overhead conveyor system, it is highly desirable to provide a conveyor cleaning arrangement which is readily installed, reliable and effective in operation, and economical to use.